The mechanism of the degradation of psaB gene product, one of the photosynthetic reaction center subunits of photosystem I, upon photoinhibition

Kintake Sonoike, Masaharu Kamo, Yukako Hihara, Tetsuo Hiyama, Isao Enami

Research output: Contribution to journalArticle

72 Citations (Scopus)

Abstract

The psaB gene product (PsaB protein), one of the reaction center subunits of Photosystem I (PS I), was specifically degraded by light illumination of spinach thylakoid membranes. The degradation of the protein yielded N-terminal fragments of molecular mass 51 kDa and 45 kDa. The formation of the 51 kDa fragment was i) partially suppressed by the addition of phenylmethylsulfonyl fluoride or 3,4-dichloroisocoumarin, which are inhibitors of serine proteases, and ii) enhanced in the presence of hydrogen peroxide during photoinhibitory treatment, but iii) not detected following hydrogen peroxide treatment in the dark. These results suggest that the hydroxyl radical produced at the reduced iron-sulfur centers in PS I triggers the conformation change of the PS I complex, which allows access of a serine-type protease to PsaB. This results in the formation of the 51 kDa N-terminal fragment, presumably by cleavage on the loop exposed to the stromal side, between putative helices 8 and 9. On the other hand, the formation of the 45 kDa fragment, which was enhanced in the presence of methyl viologen but did not accompany the photoinhibition of PS I, was not affected by the addition of hydrogen peroxide or protease inhibitors. Another fragment of 18 kDa was identified as a C-terminal counterpart of the 45 kDa fragment. N-terminal sequence analysis of the 18 kDa fragment revealed that the cleavage occurred between Ala500 and Val501 on the loop exposed to the lumenal side, between putative helices 7 and 8 o the PsaB protein.

Original languageEnglish
Pages (from-to)55-63
Number of pages9
JournalPhotosynthesis Research
Volume53
Issue number1
DOIs
Publication statusPublished - 1997
Externally publishedYes

Fingerprint

photosynthetic reaction centers
Photosynthetic Reaction Center Complex Proteins
Photosystem I Protein Complex
photosystem I
photoinhibition
Genes
Hydrogen Peroxide
hydrogen peroxide
Degradation
degradation
genes
Phenylmethylsulfonyl Fluoride
Thylakoids
Proteins
Paraquat
Serine Proteinase Inhibitors
Spinacia oleracea
paraquat
protein products
Molecular mass

Keywords

  • Hydroxyl radical
  • Light stress
  • Photosynthesis
  • Protein turnover
  • Reactive oxygen species
  • Serine protease

ASJC Scopus subject areas

  • Plant Science

Cite this

The mechanism of the degradation of psaB gene product, one of the photosynthetic reaction center subunits of photosystem I, upon photoinhibition. / Sonoike, Kintake; Kamo, Masaharu; Hihara, Yukako; Hiyama, Tetsuo; Enami, Isao.

In: Photosynthesis Research, Vol. 53, No. 1, 1997, p. 55-63.

Research output: Contribution to journalArticle

@article{459e6509602a4178a7ef877325927f12,
title = "The mechanism of the degradation of psaB gene product, one of the photosynthetic reaction center subunits of photosystem I, upon photoinhibition",
abstract = "The psaB gene product (PsaB protein), one of the reaction center subunits of Photosystem I (PS I), was specifically degraded by light illumination of spinach thylakoid membranes. The degradation of the protein yielded N-terminal fragments of molecular mass 51 kDa and 45 kDa. The formation of the 51 kDa fragment was i) partially suppressed by the addition of phenylmethylsulfonyl fluoride or 3,4-dichloroisocoumarin, which are inhibitors of serine proteases, and ii) enhanced in the presence of hydrogen peroxide during photoinhibitory treatment, but iii) not detected following hydrogen peroxide treatment in the dark. These results suggest that the hydroxyl radical produced at the reduced iron-sulfur centers in PS I triggers the conformation change of the PS I complex, which allows access of a serine-type protease to PsaB. This results in the formation of the 51 kDa N-terminal fragment, presumably by cleavage on the loop exposed to the stromal side, between putative helices 8 and 9. On the other hand, the formation of the 45 kDa fragment, which was enhanced in the presence of methyl viologen but did not accompany the photoinhibition of PS I, was not affected by the addition of hydrogen peroxide or protease inhibitors. Another fragment of 18 kDa was identified as a C-terminal counterpart of the 45 kDa fragment. N-terminal sequence analysis of the 18 kDa fragment revealed that the cleavage occurred between Ala500 and Val501 on the loop exposed to the lumenal side, between putative helices 7 and 8 o the PsaB protein.",
keywords = "Hydroxyl radical, Light stress, Photosynthesis, Protein turnover, Reactive oxygen species, Serine protease",
author = "Kintake Sonoike and Masaharu Kamo and Yukako Hihara and Tetsuo Hiyama and Isao Enami",
year = "1997",
doi = "10.1023/A:1005852330671",
language = "English",
volume = "53",
pages = "55--63",
journal = "Photosynthesis Research",
issn = "0166-8595",
publisher = "Springer Netherlands",
number = "1",

}

TY - JOUR

T1 - The mechanism of the degradation of psaB gene product, one of the photosynthetic reaction center subunits of photosystem I, upon photoinhibition

AU - Sonoike, Kintake

AU - Kamo, Masaharu

AU - Hihara, Yukako

AU - Hiyama, Tetsuo

AU - Enami, Isao

PY - 1997

Y1 - 1997

N2 - The psaB gene product (PsaB protein), one of the reaction center subunits of Photosystem I (PS I), was specifically degraded by light illumination of spinach thylakoid membranes. The degradation of the protein yielded N-terminal fragments of molecular mass 51 kDa and 45 kDa. The formation of the 51 kDa fragment was i) partially suppressed by the addition of phenylmethylsulfonyl fluoride or 3,4-dichloroisocoumarin, which are inhibitors of serine proteases, and ii) enhanced in the presence of hydrogen peroxide during photoinhibitory treatment, but iii) not detected following hydrogen peroxide treatment in the dark. These results suggest that the hydroxyl radical produced at the reduced iron-sulfur centers in PS I triggers the conformation change of the PS I complex, which allows access of a serine-type protease to PsaB. This results in the formation of the 51 kDa N-terminal fragment, presumably by cleavage on the loop exposed to the stromal side, between putative helices 8 and 9. On the other hand, the formation of the 45 kDa fragment, which was enhanced in the presence of methyl viologen but did not accompany the photoinhibition of PS I, was not affected by the addition of hydrogen peroxide or protease inhibitors. Another fragment of 18 kDa was identified as a C-terminal counterpart of the 45 kDa fragment. N-terminal sequence analysis of the 18 kDa fragment revealed that the cleavage occurred between Ala500 and Val501 on the loop exposed to the lumenal side, between putative helices 7 and 8 o the PsaB protein.

AB - The psaB gene product (PsaB protein), one of the reaction center subunits of Photosystem I (PS I), was specifically degraded by light illumination of spinach thylakoid membranes. The degradation of the protein yielded N-terminal fragments of molecular mass 51 kDa and 45 kDa. The formation of the 51 kDa fragment was i) partially suppressed by the addition of phenylmethylsulfonyl fluoride or 3,4-dichloroisocoumarin, which are inhibitors of serine proteases, and ii) enhanced in the presence of hydrogen peroxide during photoinhibitory treatment, but iii) not detected following hydrogen peroxide treatment in the dark. These results suggest that the hydroxyl radical produced at the reduced iron-sulfur centers in PS I triggers the conformation change of the PS I complex, which allows access of a serine-type protease to PsaB. This results in the formation of the 51 kDa N-terminal fragment, presumably by cleavage on the loop exposed to the stromal side, between putative helices 8 and 9. On the other hand, the formation of the 45 kDa fragment, which was enhanced in the presence of methyl viologen but did not accompany the photoinhibition of PS I, was not affected by the addition of hydrogen peroxide or protease inhibitors. Another fragment of 18 kDa was identified as a C-terminal counterpart of the 45 kDa fragment. N-terminal sequence analysis of the 18 kDa fragment revealed that the cleavage occurred between Ala500 and Val501 on the loop exposed to the lumenal side, between putative helices 7 and 8 o the PsaB protein.

KW - Hydroxyl radical

KW - Light stress

KW - Photosynthesis

KW - Protein turnover

KW - Reactive oxygen species

KW - Serine protease

UR - http://www.scopus.com/inward/record.url?scp=0030727551&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030727551&partnerID=8YFLogxK

U2 - 10.1023/A:1005852330671

DO - 10.1023/A:1005852330671

M3 - Article

AN - SCOPUS:0030727551

VL - 53

SP - 55

EP - 63

JO - Photosynthesis Research

JF - Photosynthesis Research

SN - 0166-8595

IS - 1

ER -